Exhaust the card (turn it sideways) and then a friendly figure gains a block token. You can do this once per activation because once the card is exhausted it isn’t usable until it readies again at the beginning of that hero’s next activation.

As an option you can deplete the card (turn it face down for the rest of the mission) so it is no longer usable but you can get a second block token in one use at the cost of not using it again for the rest of the mission.

Basically use it once per activation for the rest of the mission or use it twice in one activation but then it is not useable for the rest of the mission.

Get the Imperial Assault Campaign module for Vassal from http://www.vassalengine.org/wiki/Module:Star_Wars:_Imperial_Assault

The next Total Solar Eclipse holiday in 2024 in USA? See you there!

Exhausted cards of heroes ready at the start of that hero's activation.

Shield Pack allows to give power tokens, in this case the block power token:

. The attacker of defender can spend one power token when the attack is declared to add the corresponding symbol to the attack/defense results.

Shield Pack can give out 1 block power token per that hero's activation by exhausting it, and another block power tokens by depleting it. The deplete option is good during the apparent last round or if you draw the supply card late in the mission.

The cost of the ability of Shield Pack is exhaust, it doesn't cost an action. Deplete is an additional cost to use the second part of the ability. (See Abilities, page 2.) Traits like Consumable do not have inherent meaning but may be referenced by some abilities.